Auto merge of #31685 - petrochenkov:patrefact2, r=eddyb

And split `PatKind::Enum` into `PatKind::TupleStruct` and `PatKind::Path`.
This is the HIR part of https://github.com/rust-lang/rust/pull/31581.
This is also kind of a preparation for https://github.com/rust-lang/rfcs/pull/1492.

r? @eddyb

src/libsyntax/ast.rs

@@ -580,7 +580,7 @@ pub enum PatKind {
     /// An associated const named using the qualified path `<T>::CONST` or
     /// `<T as Trait>::CONST`. Associated consts from inherent impls can be
     /// referred to as simply `T::CONST`, in which case they will end up as
-    /// PatKind::Enum, and the resolver will have to sort that out.
+    /// PatKind::Path, and the resolver will have to sort that out.
     QPath(QSelf, Path),
 
     /// A tuple pattern `(a, b)`